Grease extracting ventilator system



June 13, 1967 E. GRASWICH ET AL 3,324,629

GREASE EXTRACTING VENTILATOR SYSTEM Filed Feb. 27, 1963 5 Sheets-Sheet. 1

U 7% l INVENTORS r 24 EDWARD GRASVV/CH K23 (22 \23 JACK n4 CEDARQU/ST By M A 7' 70/? NEVS June 13, 1967 i E. GRASWICH ET AL GREASE EXTRACTING VENTILATOR SYSTEM Filed Feb. 2'7, 1963 5 Sheets-Sheet 2 INVENTORS EDI MRO GRASW/CH JACK W CEDA/PQUIST ATTO/PNEVS 7 June 13, 1967 E. GRASWICH ET 3,324,629

GREASE EXTRACTING VENTILATOR SYSTEM 5 Sheets-Sheet. 3

Filed Feb. 27 1963 INVENTORS EDI 144R!) GRASI WCH JACK W CEDA/PQMST 3,324,629 Patented June 13, 1967 3,324,629 GREASE EXTRACTING VENTHLATOR SYSTEM Edward Graswich, Walnut Creek, and Jack W. Cedarquist, San Francisco, Calif, assignors to Doha-marlin Hotel Supply (30., Brisbane, Qalif, a corporation of Nevada Filed Feb. 27, 1963, Ser. No. 261,256 8 Claims. (Cl. 55-457) This invention relates to a grease extracting ventilator system.

An object of this invention is to provide a kitchen ventilator for more efficiently extracting the grease from the gases and vapors given off by the cooking surface before the air is passed into the ventilator ducts for exhausting to the outer atmosphere or for recirculating.

Another object of this invention is to provide an improved ventilator for cooking gases and vapors, said ventilator employing a fine spray or mist made up of detergent and water through which the grease carrying gases including air and vapor pass from the cooking surface; thereafter these detergent and water vapor laden gases pass through a device in which substantially all of the grease carried by said gases is deposited along with detergent in the form of a frothy foam which is collected on the top of the water and detergent solution in the circulating reservoir of the appartaus.

Another object of this invention is to provide an improved apparatus for extracting the grease from cooking gases and vapors in which the gases and vapors are passed through a fine spray of detergent and water shortly after being given off at the cooking surface and after passing through this fine spray, the gases are sucked through a rotatable bafiie arrangement at which time water and detergent and substantially all of the grease are deposited from the air and collected in a water moat in the form of a foamy emulsion which is allowed to drain out of the bottom of the water moat and is collected in the water and detergent reservoir on the top surface of the water and detergent.

Other and further objects of this invention will be apparent to those skilled in the art to Which it relates from the following specification, claims and drawing.

In accordance with this invention there is provided an improved ventilator system for use with cooking surfaces in which grease extracting efficiency is greatly improved and in which maintenance costs and fire hazards are reduced.

In this grease extracting ventilator there is provided a pump and nozzle system for producing a fine spray of water and detergent which is projected across the passage through the ventilator and forms a misty curtain through which the grease carrying gases and vapors leaving the cooking surface are sucked and pass shortly after leaving the cooking surface. The water and detergent spray are at room temperature and when the cooking gases carrying grease are drawn upward therethrough an emulsion is produced. This emulsion is deposited from the air stream in a rotatable baffle arrangement into which it is lifted by means of suction produced by the exhaust blower that is located in the upper part of the ventilator ducts. The emulsion thus deposited contains practically all of the grease from the cooking surface so that substantially no grease is exhausted to the outer atmosphere or is recirculated through the purified air. The rotatable baffle arrangement is enclosed in an annular housing that is provided with a perforated bottom panel which is held or positioned above a water moat. Thus as the rotatable battle is rotated the grease, water and detergent emulsion drops down into the water moat through the perforated baffle. The water moat is provided with a water seal in the bottom thereof, and the water collected therein is prevented from draining from this moat by the suction provided by the aforesaid blower until the weight of the water exceeds the holding power of this suction. At such time some of the water runs out through the water seal carrying some of the emulsion with it down through the drain which is connected to the reservoir for holding the water and detergent. In this reservoir the grease, water and detergent emulsion collected from the aforesaid water moat is accumulated as a frothy foam on the top of the water and detergent solution. The solution is pumped out of the bottom part of the reservoir and into the water spray nozzles through which it is forced at sufficient velocity so that the spray forms a fine misty curtain extending completely across the ventilator passage. The Water and detergent solution thus function in a continuously circulating system because the ventilator is equipped wtih a drain to which the spray drains and to which the grease emulsion also drains, and this drain is connected to the reservoir.

The rotatable baffle structure functions to separate the trapped water from the air also so that this Water is passed through the perforated bottom of the rotatable baffle structure and is also collected in the water moat in addition to the frothy foam collected therein for draining.

Other details of this invention and a working embodiment thereof will be set forth in the following specification and the drawing, in which, briefly:

FIG. 1 is a front view of an embodiment of this apparatus;

FIG. 2 is a side View;

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 1;

FIG. 4 is a sectional view taken along the line 4-4 of FIG. 3;

FIG. 5 is a sectional view taken along the line 5-5 of FIG. 3, and

FIG. 6 is a rear view of this apparatus.

Referring to the drawing in detail, there is shown an embodiment of this invention provided with wall structure 10 illustrated in the front view of FIG. 1 and side view of FIG. 2. The front of this wall structure is provided with removable panels 11 and 12 to provide easy access to the inside for servicing if necessary. Part of the front wall structure 10a is inturned and the spray nozzle arrangement, which will be described hereinafter, is positioned on the inside of this wall structure. The panel 1012 which is positioned slightly below the water and detergent spray 24 is also removable so that access to this part of the Wall structure also may be readily obtained. The horizontal wall structure 10c is provided to define the air inlet passage and assist in guiding the cooking gases and vapors into the ventilator structure from the cooking surface 10d. The back 15 of the ventilator wall structure is provided with panels 16, 17, 18 and 19 of which panels 16 and 18 are removable. Panels 17 and 18 are angularly disposed with respect to each other and form a spray trap whereby the spray is guided downward toward the trough 20 and drain 21.

The water and detergent solution is fed to the spray nozzles 23 through the pipe 22 which is connected to the pump as shown in FIG. 6. Thus a supply of water and detergent solution is fed to the pump 38 from the bottom part of the tank 35 and the pump supplies the water and detergent solution under pressure to the nozzles 23 so that overlapping sprays 24, as shown in FIG. 4, are projected across the ventilator passage. In this way the cooking gases and vapors produced at the cooking surface 10d and sucked up through the ventilator structure by the exhaust blower 14a must pass through these water and detergent sprays on their way up'into the ventilator structure. The grease laden cooking gases and vapors, after passing through the sprays 24, impinge the vanes 27 of the rotatable bafile 26. This rotatable bafile may be constructed as disclosed in our application Ser. No. 125,889, filed May 25, 1961, now Patent No. 3,077,717, and in US. Patent No. 2,793,712 so that it provides a plurality of radially extending and curved paths for the cooking gases. These paths lead to the inner wall of the housing 25 and thence upward and inward to provide a tortuous route for these gases. This baffle structure functions to separate the grease emulsion from the gases and the separated grease emulsion is dropped out of the rotatable baflle housing 25 through the holes 28 which lead to the moat formed by the members 29 and 30.

The annular bottom of the rotatable bafile housing 25 is provided with a plurality of apertures 28 through which the grease laden emulsion drops down into the water moat 29. This water moat is provided with an inner annular member that extends up to the bottom of the housing of the rotatable bafile to which it is attached. The housing 25 is supported on the member 29 which forms the inner part of the water moat and this member 29 is supported by the annular member 30 which is provided with a small trough 32.

The member 29 is provided with a downwardly turned lip 31 that rests in the trough 32 rather loosely so that water, detergent and grease emulsion drains out through this trough when the level thereof builds up in the moat to a level such that the suction of the exhaust blower 14a cannot retain it. At such time some of the liquid drains from the moat and passes down to the drain 21 which is connected to the reservoir or tank 35, as shown in FIG. 6. The water and detergent returned to this tank through the line 21 is recirculated by the pump 37. However, the grease emulsion which is in the form of a foamy material, collects at the top of this tank and it is removed therefrom and passed into a waste line. The solution is pumped out of the tank 35 by the pump 37 which is coupled to the drive motor 36 and it is passed into the line 22 which is connected to the nozzles 23 as previously described, at a pressure such that the jets issuing from the nozzles 23 form sprays 24 that are projected substantially horizontally into the V-shaped spray trap formed by the panel members 17 and 18. A suitable relief valve 39 is connected to the line 22 and to the tank 35 at 41 so that the pressure in the line 22 may be controlled. The trap formed by members 17 and 18 functions to collect the spray produced when the solution hits the wall structure. The collected or trapped solution is guided down to the trough 20 which is connected to the drain 21 so that the solution may be reused.

The detergent solution sprayed into the inside of the ventilator structure through the nozzles 23 also functions to keep the inside wall surfaces of the ventilator clean and no greasy material adheres to these walls or accumulates thereon, thus materially reducing fire hazard. Sufficient detergent must be present in the water solution to accomplish this result as otherwise some of the greasy material would adhere to the wall surfaces. Any powdered dishwashing machine detergent, for example, detergents sold under the name of Calgonite may be used. One ounce of this detergent is used to one gallon of water at room temperature. Detergents having meta-phosphate, meta-silicate, sesqui-silicate, and a Pluronic wetting agent are suitable for use in this apparatus. If the detergent solution is to come in contact with aluminum surfaces, then an aluminum inhabitor must be added.

While we have shown a preferred embodiment of the invention it will be understood that the invention is capable of variation and modification from the form shown so that its scope should be limited only by the scope of the claims appended hereto.

What we claim is:

1. In apparatus for extracting grease from gases given off of a cooking surface, the combination of ventilator Wall structure positioned to receive grease laden gases from a cooking surface, said ventilator wall structure having means for defining a cooking gas exhausting passage therethrough, means for sucking the grease laden gases into said passage, means for producing a spray of detergent solution across said passage so that the grease laden gases pass through said spray, rotatable bafile means, wall structure supporting said rotatable batile means in said gas-exhausting passage, said wall structure including annular wall structure partially enclosing said rotatable baflle means and in close proximity to the end portions of said rotatable bafile means, said rotatable baffie means receiving said gases after they pass througlr said spray, said rotatable baffie means depositing thegrease therefrom in said annular Wall structure in the form of an aerated foam soaked with liquid from said spray, said annular wall structure having a bottom through which said foam is discharged, and a trough for" receiving said foam, said trough having a drain con nected thereto.

2. In apparatus for extracting grease from gases given off of a cooking surface, as set forth in claim 1, further comprisingly angularly disposed baffles attached to said ventilator wall structure above said trough and positioned to receive said spray of detergent solution after said spray is traversed by the grease-laden gases, said angularly disposed bafiies being positioned one above the other and the upper one overhanging the lower one so that the spray impinging said angularly disposed baffles flows down surfaces thereof to said trough.

3. In apparatus for extracting grease from gases given off of a cooking surface, as set forth in claim 1, further characterized in that said wall structure supporting said rotatable bafiie means includes a baffie attached to said ventilator wall structure and extending into said gasexhausting passage, and additional wall structure attached to the bottom of said annular wall structure and resting loosely on said last-mentioned baffle.

4. In apparatus for extracting grease from gases given off of a cooking surface, as set forth in claim 3, further characterized in that said bafile attached to said ventilator wall structure and said additional wall structure to form a moat under the bottom of said annular wall structure for collecting the aerated foam soaked with liquid therein.

5. In apparatus for extracting grease from gases given ofi of a cooking surface, as set forth in claim 4, further characterized in that said additional wall structure rests loosely on said baflle attached to said ventilator wall structure and the liquid collected in said moat drains out of said moat through the loose joint between said additional wall structure and said batlle, and an exhaust blower positioned in said gas-exhausting passage above said rotatable battle means to provide suction on the upper surface of the liquid in said moat and thereby control the draining of said liquid from said moat through said loose joint.

6. In apparatus for extracting grease from gases given off of a cooking surface, the combination of ventilator wall structure positioned to receive grease laden gases from a cooking surface, said ventilator wall structure having means for defining a cooking gas exhausting passage therethrough, means for sucking the grease laden gases into said passage, means for producing a spray of detergent solution across said passage so that the grease laden gases pass through said spray, rotatable batile means, wall structure supporting said rotatable bafile means across said gas exhausting passage, said batille means having a plurality of tortuous paths therethrough for receiving said gases after they pass through said spray for depositing the grease therefrom in the form of an aerated foam soaked with liquid from said spray, a water moat formed in said wall structure and positioned under said rotatable baffle means, a part of said wall structure above said water moat having apertures therein through which the foam and liquid drop into said moat, the foam and liquid being drained from said moat after reaching a predetermined level therein, a reservoir in which the foam is collected and means for recirculating the liquid from said reservoir through said spray producing means.

7. In a method of extracting grease from cooking gases and vapors the steps of producing a fine spray of a solution of detergent and Water, passing the cooking gases through said spray, thereafter subjecting the cooking gases to centrifugal action for separating substantially all of the grease and detergent from the cooking gases, collecting this grease and detergent as a foamy substance in a Water moat and draining fluid from the Water moat as said substances accumulates therein.

8. A method of extracting grease from cooking gases and vapors as set forth in claim 7, further comprising subjecting the top of the Water moat to suction and allowing fluid to drain from the bottom part of said moat as the liquid head builds up in said moat, collecting the fluid drained from said moat and supplying the collected fluid to said spray,

References Cited UNITED STATES PATENTS Lambert et al 55--258 X Roche, Jr. et a1. 55-257 X Clark et a1. 55--257 Graswich et al. 55404 Urnbricht et a1. 55-257 X Graswich 98115 Graswich 98-115 Graswich et 'al. 55-404 HARRY B. THORNTON, Primary Examiner. 15 ROBERT F. BURNETT, LOWELL H. MCCARTER,

Assistant Examiners. 

1. IN APPARATUS FOR EXTRACTING GREASE FROM GASES GIVEN OFF OF A COOKING SURFACE, THE COMBINATION OF VENTILATOR WALL STRUCTURE POSITIONED TO RECEIVE GREASE LADEN GASES FROM A COOKING SURFACE, SAID VENTILATOR WALL STRUCTURE HAVING MEANS FOR DEFINING A COOKING GAS EXHAUSTING PASSAGE THERETHROUGH, MEANS FOR SUCKING THE GREASE LADEN GASES INTO SAID PASSAGE, MEANS FOR PRODUCING A SPRAY OF DETERGENT SOLUTION ACROSS SAID PASSAGE SO THAT THE GREASE LADEN GASES PASS THROUGH SAID SPRAY, ROTATABLE BAFFLE MEANS, WALL STRUCTURE SUPPORTING SAID ROTATABLE BAFFLE MEANS IN SAID GAS-EXHAUSTING PASSAGE, SAID WALL STRUCTURE INCLUDING ANNULAR WALL STRUCTURE PARTIALLY ENCLOSING SAID ROTATABLE BAFFLE MEANS AND IN CLOSE PROXIMITY TO THE END PORTIONS OF SAID ROTATABLE BAFFLE MEANS, SAID ROTATABLE BAFFLE MEANS RECEIVING SAID GASES AFTER THEY PASS THROUGH SAID SPRAY, SAID ROTATABLE BAFFLE MEANS DEPOSITING THE GREASE THEREFROM IN SAID ANNULAR WALL STRUCTURE IN THE FORM OF AN AERATED FOAM SOAKED WITH LIQUID FROM SAID SPRAY, SAID ANNULAR WALL STRUCTURE HAVING A BOTTOM THROUGH WHICH SAID FOAM IS DISCHARGED, AND A TROUGH FOR RECEIVING SAID FOAM, SAID TROUGH HAVING A DRAIN CONNECTED THERETO. 